SerenaReplTool: Make clear that print and other output functions cannot be used [skip ci]

src/serena/tools/repl_tools.py

@@ -34,8 +34,9 @@ class SerenaReplTool(Tool, ToolMarkerOptional, ToolMarkerBeta):
         calls).
 
         The code is executed like a notebook cell: if its last statement is an expression, the expression's value is
-        the result. Results are rendered in a form suitable for you; lists are rendered element-wise,
+        the result. Results of facade methods are rendered in a form optimised for you; lists are rendered element-wise,
         strings are passed through unchanged.
+        You cannot use `print` or other output functions to return content; only use the last expression to return content.
 
         Output size: methods with a `max_answer_chars` parameter limit the size of the rendered result (-1 uses the
         configured default). If the limit is exceeded, a shortened result (or no content) is rendered instead;